Flow deformation press



'July 28, 1964 K. GRIESINGER FLOW DEFORMATION PRESS Filed April 28. 1961 INVENTOR ATTORNEYj United States Patent 3,142,380 FLOW DEFORMATION PRESS Karl Griesinger, Jebenhausen, Wurttemberg, Germany,

assignor to L. Schuler AG, Goppingen, Wurttemberg,

Germany Filed Apr. 28, 1961, Ser. No. 106,390 Claims priority, application Germany May 4, 1960 3 Claims. (Cl. 207-6) The invention relates to a flow deformation press.

In presses of various kinds it is already known to provide means between the connecting rod and the ram for exactly adjusting the position of the ram at bottom dead centre. These ram adjusting means serve to compensate minor tolerance differences when the pressing tools have been exchanged.

Known flow deformation presses have also been equipped with such devices. However, the problem in flow deformation presses differs somewhat from that arising in other presses because in flow deformation presses the punch heats up considerably, whereas in other presses or stamping machines the tool does not become nearly as hot as the punch in a flow deformation press. The relatively high temperature which the punch assumes in course of the flow deformation of the Work causes a corresponding amount of expansion of the punch.

Whenever work on a flow deformation press is interrupted for a longer or shorter period the punch at forward dead centre is therefore at first a little further away from the floor of the die than when the press has been in operation for a time and the punch has assumed a temperature at which the heat lost by radiation is in equilibrium with the heat accepted by the punch. Until this temperature has been reached the press will produce pressings having a floor section slightly thicker than the designed section and a length which may possibly be less than the designed length.

Furthermore, owing to the greater distance of the punch in dead centre position from the floor of the die the pressure applied to the blank is less in case of a cold punch than that applied when the punch is hot. If these differences which arise whilst the press warms up are not considered admissible, then the operator of the machine must repeatedly readjust the dead centre position during this period. If the ram adjusting means are built in between the connecting rod and the ram this is impossible to do unless the press is first stopped.

The invention therefore consists in providing for accurate adjustability of the position at forward dead centre of the tool attached to the ram by making the press table, which bears on a back rest for taking up the thrust, adjustably displaceable in the direction of the stroke of the ram.

The special advantage afforded by the invention is that the dead centre position can be readjusted in a flow deformation press equipped according to the invention whilst the machine is in operation. Moreover, adjustment can be very easily accomplished for instance in one embodiment of the invention by moving an adjustable wedge which is interposed between the table and its back rest. In hitherto known machines, an adjusting means interposed between connecting rod and ram cannot be embodied in a simple adjustable wedge and are necessarily of much greater complexity in construction.

Adjusting means of the kind proposed by the invention may, in case of need, also be used to compensate for a major difference in play. This is a very substantial asset because in toggle presses it is in principle conventional to provide for adjustable displaceability of the bearing support of the rear toggle lever in the direction of the stroke of the ram. However, adjusting means of this 3,142,380 Patented July 28, 1964 tZE.

latter kind permit only minor deviations to be compensated for because the required displacement of this bearing support, in order to allow for major tolerances of play, would change the thrust and other properties of the press because of the resultant displacement of the toggle joint.

Other features of the invention will emerge in the course of the following description of a preferred embodiment of the invention in conjunction with the appended claims and the accompanying drawing. The features of the invention may be severally or jointly employed in embodiments of the invention.

The sole figure of the drawing shows only those parts of a press according to the present invention which are necessary for a understand of the invention.

In the illustrated embodiment a ram 2 which carries a punch 3 is slidably guided in a press frame 1. A suitable die 4 for the production of a flow deformation pressing is secured to a press table 5 which is slidably guided in the direction of ram reciprocation in keyways 6 and 7 in the frame 1 of the press. The table 5 is supported by a back rest 9 formed by the press frame, which takes up the thrust of the ram, an adjustable wedge 8 being interposed between the back of the table 5 and the back rest 9. The rear face of the table 5 has a slanting surface 10 which slopes at the same angle as the abutting face 11 of the wedge 8. The wedge can be slidably moved across the direction of reciprocation of the ram and in the direction of the opening angle of the wedge. For setting the wedge 8 at least one screw 12 is provided which works in threads 13 in the wedge 8, whereas its other end carries a plate 14 which is rotatably held in the frame in a manner incapable of axial displacement. The extreme end of the screw 12 is fitted with a handwheel 15.

If desired, two screw spindles may be provided for adjusting the wedge 8. In such a case it is preferred to couple the screws by means of a chain drive which ensures synchronous rotation of the two screw spindles. The press table can thus be readjusted whilst the press is in operation, since the handwheel and the screw spindle 12 can be easily rotated in either direction during the idle stroke of the ram.

The wedge is formed with a recess 16 for a rod 17 which is attached to the table 5 and which projects through a hole 18 drilled through the back rest 9 for the table. The external end of this rod 17 carries a plate 19 and a spring 20 interposed between said plate and the outside face of the frame back rest 9. The spring 20 thus presses the plate 19 outwards and hence maintains table 5 in contact with the sloping face of wedge 8.

What I claim is:

1. In a toggle press, the combination comprising reciprocable ram means, a press frame including stationary back rest means, press table means between said ram means and said back rest means, substantially perpendicular to and adjustable in the direction of reciprocation of said ram means, adjusting means including a wedge member interposed between said back rest means and said press table means, guide means for said press table means along at least part of its path of adjustment, said guide means including at least one portion of said press frame in the region of said press table means, substantially parallel with said direction of reciprocation and having a keyway therein, said press table means having at least one peripheral portion in mating engagement with said keyway, a rod member rigid at one of its ends with said press table means and protruding through said back rest means substantially parallel to said direction of reciprocation, and resilient means including a spring surrounding said rod member for urging the other end thereof away from said back rest means and thus said press table means toward away from said ram means.

2. In a toggle press, the combination according to claim 5 1, wherein said press table means and said wedge member have adjoining engaging surfaces slanting with respect to said direction of reciprocation.

3. In a toggle press, the combination according to claim 1, wherein said adjusting means includes at least one spindle member operatively connected to said Wedge member and protruding beyond said press frame, whereby 4 said regulation may be performed while the press is in operation.

References Cited in the file of this patent UNITED STATES PATENTS 45,187 Spaulding 2. Nov. 22, 1864 824,866 Horton July 3, 1906 994,686 Michell June 6, 1911 1,591,929 Richardson July 6, 1926 2,017,784 Clouse Oct. 15, 1935 2,633,765 Glasner Apr. 7, 1953 2,954,121 Benson Sept. 27, 1960 

1. IN A TOGGLE PRESS, THE COMBINATION COMPRISING RECIPROCABLE RAM MEANS, A PRESS FRAME INCLUDING STATIONARY BACK REST MEANS, PRESS TABLE MEANS BETWEEN SAID RAM MEANS AND SAID BACK REST MEANS, SUBSTANTIALLY PERPENDICULAR TO AND ADJUSTABLE IN THE DIRECTION OF RECIPROCATION OF SAID RAM MEANS, ADJUSTING MEANS INCLUDING A WEDGE MEMBER INTERPOSED BETWEEN SAID BACK REST MEANS AND SAID PRESS TABLE MEANS, GUIDE MEANS FOR SAID PRESS TABLE MEANS ALONG AT LEAST PART OF ITS PATH OF ADJUSTMENT, SAID GUIDE MEANS INCLUDING AT LEAST ONE PORTION OF SAID PRESS FRAME IN THE REGION OF SAID PRESS TABLE MEANS, SUBSTANTIALLY PARALLEL WITH SAID DIRECTION OF RECIPROCATION AND HAVING A KEYWAY THEREIN, SAID PRESS TABLE MEANS HAVING AT LEAST ONE PERIPHERAL PORTION IN MATING ENGAGEMENT WITH SAID KEYWAY, A ROD MEMBER RIGID AT ONE OF ITS ENDS WITH SAID PRESS TABLE MEANS AND PROTRUDING THROUGH SAID BACK REST MEANS SUBSTANTIALLY PARALLEL TO SAID DIRECTION OF RECIPROCATION, AND RESILIENT MEANS INCLUDING A SPRING SURROUNDING SAID ROD MEMBER FOR URGING THE OTHER END THEREOF AWAY FROM SAID BACK REST MEANS AND THUS SAID PRESS TABLE MEANS TOWARD SAID BACK REST MEANS IN CONTIUOUS ENGAGEMENT WITH SAID WEDGE MEMBER, WHEREBY STEPLESS REGULATION OF THE DEAD CENTER POSITION OF THE PRESS IN INSURED BOTH TOWARD AND AWAY FROM SAID RAM MEANS. 